影响摩托车零部件质量的原材料因素

原材料的外观质量、化学成分、低倍组织、脱碳层深度、非金属夹杂物、显微组织(晶粒度)和顶锻试验等7个方面,对摩托车零部件质量的影响均较大。高级优质级别的中碳钢、低中碳合金钢化学成分应达到标准的中上限,且强化元素C、Cr、Mn、Mo等平均含量应高于标准要求的中限。低倍组织中的中心疏松、一般疏松、方形偏析允许≤1.5级,不允许存在白点、缩孔、气泡、翻皮等缺陷。钢材的脱碳层深度应不大于公称直径的1%;显微组织中带状组织0～3级为合格,魏氏组织0～2.5级为合格。摩托车零部件原材料的实际晶粒度应控制在6～8级。

The Raw Material Factors Influencing the Parts Quality of Motorcycles

The 7 aspects,such as the appearance quality,macrostructure chemical constitution,depth of decarbonized layer,non-metallic inclusions,fibrous tissue（grain size） and upsetting test hare greater influence upon the ports quality of motorcycles.The chemical constitution of high-class high quality medium carbon steel, low carbon alloy steel should reach the medium and superior limits specified in the standards and the average contents of the intensified elements C,Cr,Mn,Mo should be higher than the medium limit in the standard.The central loose,general loose and square segregation are allowed to be≤1.5 with flakes,shrinkage holes,air bubbles,skull patch not allowed.The depth of decarbonizes layer of the steel should.mot be greater than 1%of the nominal diameter;the banded structure in the fibrous tissue of 0～3 grade is considered to be qualified,the widmanstatten structure of 0～2.5 is taken as qualified.The grain size of the raw materials for motorcycle should be controlled in 6～8 grade.